Electric car heater



Oct. 2, 1934. w. G. HARTwlG ELECTRIC GAR HEATER 2 Sheets-Sheet l Filed March 7. 1952 Alv @N QN lllIlllllill/llIlIldIIIIIIIIVIIIIIIIIIIIII "IMIIIIIIMHII QN NM, WN

IF FIF E Oct. 2, 1934. w. G, HARTWIG ELECTRIQ CAR HEATER 2 sheets-smet 2 Filed March 7, 1952 Patented Oct. 2, 1934 UNITED STATES PATENT OFFCE ELECTRIC CAR HEATER poration of Illinois Application March 7, 1932, Serial No. 597,101

v3 Claims.

This invention relates to improvements in electric car heaters of the type which are supported or suspended beneath the seats in electric rail- Way cars or in similar conveyances.

It is an object of the invention to disclose a construction which may -be readily assembled, which will conform in use to the underwriters requirements insofar as preventing excessive heating of the terminal connections and which will direct the major portion of the heat downwardly against the floor of the car without undue heating of the seat above the heater unit.

It is a specific object of the invention to form the casing of the heater unit with a reflector plate above the electrical resistance units and provide a partitioned heat insulated chamber above the reflector plate toI prevent excessive heating of the top part of the heater.

Further improvements of the present invention are directed to the construction of the terminal box which is supported'by and insulated from an end wall of the main body of the heater casing and the design and support for the terminal extensions between the resistance units and the terminal box which conduct the current 'to the heater units.

Additional improvements and features of novelty in the construction will be more readily apparent from the complete description taken in connection with the attached drawings, in which Figure 1 is a bottom View of the complete heater unit;

Figure 2 is a vertical longitudinal section;

Figure 3 is an end elevation, certain parts being removed for clearness;

Figure 4 is a vertical transverse section taken on the plane indicated 4-4 in Figure 2;

Figure 5 is a detail section showing the terminal extensions, and

Figure 6 is a detail section taken on the plane indicated 6-6 in Figure 5.

The heater unit is adapted to be suspended Fbeneath the seat of a street car in such relation lthat a number of such heaters will serve as a means for keeping the car warm and the heat jwill be directed downwardly towards the door of the car to cause more equal distribution of the heat throughout the car without communication to a disagreeable degree to the seat which is above the heater. The end walls 10 and 12 are formed with outwardly directed flanges 14 and 16 at their upper portions which serve as the hangers for suspending the heater. A bottorn wall 18 extending longitudinally between the end Walls 10 and 12 is formed arcuate in cross (Cl. 21B-34) section and provided with a plurality of openings 20 whereby the Wall 18 is in the form of a grille. The reticulated bottom wall 18 is in engagement at its upper longitudinal edges with an arcuate copper reflecting plate 22, the co-n- 6of: cave surface of which faces downwardly as shown in Figure 4. Above the reflecting plate 22 there is arranged a cover casing 24 in the form of a closed chamber having an arcuate bottom Wall 26 and a flat top wall 28 united at their longi- 6b tudinal edges by the downwardly and inwardly inclined side walls 30. The space within the cover portion 24 is divided by a baiile plate 32 into a pair of side chambers 34-34 and a top chamber 36. The cover parts are attached to 70' the end walls 10 and 12 which close the ends of the air chambers through screws 38 extending through the top wall 28, the spacing bushings 40, the baie plate 32, the bottom wall 26 and the copper reector 22 and finally into threaded 75 engagement with brackets 42 iixed to the end Walls 10 and 12.

Within the space between the arcuate grille 18 and the copper reflector 22 is mounted a pair of longitudinally extending resistance units 44 30: fastened at their ends to brackets 46 fixed to the end walls 10 and 12. As shown in Figure 6 each end of the resistance units is flattened as shown at 48 and spaced from the brackets 46 by an insulating bushing 50 which in turn re- 85; ceives an insulating bushing 52 passing through the flattened end 48 of the resistance unit and held by a shoulder 54. A screw bolt 56 extends through the bushing 52 and into threaded engagement with the bracket 46 for tightly clamp- 90; ing the resistance unit in place. A pair of terminals 58 are provided at one end of each of the resistance units 44. The terminals 58 include upwardly directed threaded studs 60 upon which are fastened nut members 62. The ter- 95- minal extensions or lead-in strips 64 are formed channel-shaped in cross section having depending side flanges 66. The ends of the terminal extensions 64 which connect to the nut members 62 are securely fastened thereby by beadloo ing over the upper end of the nuts, as shown at 68. The terminal extensions 64 extend through the end wall 10 and are insulated therefrom by a bushing 70. The bushing also serves as a spacing member between the end wall 10 and a 1Q5 radiating shield '72 which is adapted to direct the heat away from the contacts to the terminal extensions. Additional spacing bushings 74 may be provided, as shown in Figures 1 and 2.

The terminal extensions 64 are provided at H0 to a top plate 88 and closed at one end by aV` bracket 90 receiving the wires 80 ora wire con-Y duit by opening 92. Theterminal box is iurther protected by an insulating plate '71 spaced from the radiating shield 72. The terminal eX- tensions are held against outward'movement with respect to the bushing by pins94.l

The heat radiated from the resistance unit 44 is reflected by the copper shield 22 in a downward direction and it is found that the copper shield prevents the Vabsorption of too much heat bythe partitioned air spaces 34and 36. The

Vmajority of the heat is therefore directed downwardly through the grille 20 and against the floor of the oar. The enclosure of the connections of wires to the terminal Yextensions-64 is suiiiciently heat-insulated from the main body of the heater to maintain Ya temperature not over 250 F. in accordance with the requirements of the underwriters.

I claim:

1. An electric car heater comprising a suspended casing composed of a pair of end walls,

a .grille-shaped bottom wall extending between `and supported by said end walls, a reflector plate extending between said end Walls above said bottom wall, a top casing part open at its ends adapted to rest directly uponV the top of said reflector in position between the end walls such that the open ends of said top casing part are closed by said end walls, and an electric resistance heating unit extending between said grilleshaped bottom wall and said reflector supported by and insulated from the end walls of said casing.

2. Anvelectric car heater comprising 'a pair of suspended end walls, a grille-shapedrbottom wall longitudinally extending between said end walls, said bottom wall being arcuate in cross section, an*v electric resistance heating unit supported at its ends and insulated from said end walls, a reflector plate longitudinally extending from said end walls above said resistance unit, said reflector plate being arcuate in cross section and Vadapted to reect the heat downwardly and a top member forming an insulating partition longitudinally extending between said end walls and including top and bottom walls and enclosing side walls, the bottom wall of said insulating partition being shaped to conform to the shape` of said reector plate, whereby said insulating partition rests upon and is supported by=said reflector plate. v

3. vAn electric car heater comprising a pair of end walls, a grille-shaped bottom Wall extending longitudinally between said end walls, a plurality of electrical resistance heating units supported at their ends and insulated from said end walls above said grille-shaped bottom wall, a reflector plate -longitudinally extending between said end walls, said reflector plate being arcuate in clo section with its conca-Ve side facing downwardly towards said resistance unit, means exe tending between said endV walls immediately above said reector plate forming a closed air chamber and a baie plate extending longitudinally within said chamber to preventundesirable heating ofthe top. part of the heater unit.

f WILLAM G. HARTWIG. l 

